import queue

var q = Queue()
q.enQueue(1)
q.enQueue(2)
q.enQueue(3)
println(q.size(), q.isEmpty())

println(q.deQueue())
println(q.deQueue())
println(q.size(), q.isEmpty())

q.enQueue(4)
q.enQueue(5)
q.enQueue(6)
println(q.size())
println(q.front())
println(q.tail())

println(q.deQueue())
println(q.deQueue())
println(q.deQueue())
q.deQueue()
println(q.size(), q.isEmpty())
